That is not a security issue, if you want visitors to signup, you must enable signup, however, wpdm signup form has the option to enable/disable captcha and email verification. Doc:
When I go to settings there is no ‘Hi, Enable user registration from Dashboard->Settings->General Page. Check the anyone can register option there.’ am I seeing something different or is this feature in paid version only? This plugin was perfect for my need until keep getting error user egistration is disabled. Have looked everywhere but the option just does not exist.